FIG. 5.

Transfer of GlcNAc-1-P to Und-P. All assays were carried out at 37°C for 15 min in triplicate. One unit of enzyme activity was defined as 10⁻³ pmol of GlcNAc incorporated/min/mg protein. (A) UDP-GlcNAc-dependent activity of WecA_FLAG-5×His in the presence of excess Mg²⁺ (16.7 mM) and Mn²⁺ (3.1 mM). (B) Mg²⁺- and Mn²⁺-dependent enzyme activity of WecA_FLAG-5×His. Assays were carried out at 37°C for 15 min with a fixed concentration of UDP-GlcNAc (131.4 pmol), 40 μg of total membranes from an MV501(pKV1) preparation, and different concentrations (0 to 3 mM) of Mg²⁺ and Mn²⁺.